Process of printing



Patented Jan. 23, 1334 PROCESS OF PRINTING George Bivat, Paterson, N. J., assignor to Celanese Corporation of America, a corporation of Delaware No Drawing. Application August 2, 1929 Serial No. 383,173

BGlalms.

This invention relates to a process of printing yarns and/or fabrics, especially fabrics made of containing organic derivatives of cellulose.

An object of my invention is to apply the principle of discharge printing to fabrics to obtain clear white discharges and colored discharges which do not rub.

, Another object of my invention is to utilize vat colors for obtaining discharge prints on fabrics made of 'or containing cellulose esters or ethers.

A further object of my invention is to effect discharge printing on fabrics made of or containing cellulose derivatives with vat and chrome colors in the presence of a swelling agent and a reducing agent.

Other objects and advantages will appear from the following detailed description.

Heretofore it has been impossible to obtain good clea'r discharge prints on fabrics utilizing chrome or vat colors. This was particularly true of fabrics made of or containing organic derivatives of cellulose. Clear white discharges on the latter type of fabric were also diflicult to obtain.

I have now found that it is possible to secure excellent colored discharges with chome and/or vat colors if the latter are applied in printing pastes containing suitable reducing agents and agents which will insure thorough penetration of the vat colors. Improved results in white discharges have also been obtained as a result of my invention, which may be described as a super reduction process. 1

By way of example the invention will be described as applied to fabrics made of or containing cellulose acetate but my process is also applicable to fabrics made of or containing other organic derivatives of cellulose such as cellulose esters (cellulose formate, cellulose propionate) and cellulose ethers (methyl cellulose, ethyl cellulose, etc.) This invention is also applicable to fabrics generally whether the same be made of or v contain silk, cotton, wool or artificial silk of the reconstituted cellulose type.

A feature ofvmy invention is the employment of suitable reducing agents in connection with the vat or chrome colors. By a proper selection ofthe reducing agent and its proper admixture with swelling and penetrating agents, vat colored discharge prints are obtained which are absolute- 5 by my invention, which may perhaps be best described as a super reduction process. The vat or chrome color is mixed with a suitable thickening agent such as gum arabic or tragacanth to which is added a swelling agent or agents, such as phenol or alcohol, for the cellulose derivative, reducing agents such as zinc formaldehyde sulfoxylate, sold under the trade-marks Decroline and Protolln, or

sodium formaldehyde sulfoxylate, sold under the trade-mark Formopon, and sodium I oxalate. Preferably some dithio glycol, sold under the trade-marl: Glyazine and caustic soda are also added to the paste, the former acting as a penetrating agent and as a solvent for the vat color. Instead of Glyazine, other glycol derivatives such as thiodiglycol, ethylene glycol, chlor derivatives of the glycols, triethanolamine, etc. may be used.

To obtain best results, the printing paste with the above ingredients for color discharges, should be allowed to stand at least 24 hours after it is prepared before the same is used. A longer period is preferable since it insures a better reduction of the vat color. I have found that the color has a tendency to rub if the paste is used before the expiration of 24 hours. The prolonged standing of the paste after its preparation apparently results in a better reduction of the color, yielding colored prints which do not rub,

Where chrome colors are employed, the phenol used in the paste should be neutralized, preferably .with caustic soda but when vat colors. are employed complete neutralization of the phenol is not essential. For white discharges Decroline ives slightly better results than Protolin but the latter is to be preferred where colored discharges are desired.

pastes which I have found to give excellent results but my invention is not to be considered as limited to these examples. I

Examples I and II are for white discharges and examples III and iv are for colored discharges.

The following are a few examples of printing Example I Grams per litre Decroline 250- Alcohol 60 Phenol 10 Water Arabic or tragacanth gum (1:1) 500 E'flmtple u Grams per litre Protolin 250 Phenol- 10 Alcohol 10 Pyrosallic acid 10 Water 180 Arabi or tragacanth gum 540 Example III Grams per Algol Scarlet G paste (Color Index 1129) reduced 150 Decroline 80 Formop n 20 Water 60 Phenol 10 Glyazine 50 Sodium oxalate 50' Caustic soda 40-60 Arabic or tragacanth gum (1:1). 320

Example IV Grams per Algol Scarlet G paste (Color Index 1129) reduced 150 Protolin 150 Water 60 Phenol 10 Glyazine 50 Sodium oxalate 50 Caustic soda -1 40-60 Arabic or tragacanth gum (1:1) 320 The fabric after being treated with the above pastes in any suitable manner is passed through a Mather Platt for 10 minutes with as much moisture as possible.

Although Algol Scarlet G paste (Color Index 1129) is the only vat dye specified in the examples, this invention is not limited to this partlcular dye. Other vat dyes, especially the anthraquinone vat dyes can be used with excellent results. Also other swelling agents may be employed in place of alcohol.

The foregoing detailed description is given merely by way of illustration and many variations may be made therein without departing from the spirit of this invention.

.Having described my invention what I claim and desire to secure byLetters Patent is:

1. Method of discharge printing fabric which comprises treating a dyed fabric containing celluose acetate with a printing paste containing a swelling agent for the fabric under treatment, a vat color and a penetrating agent which is also a solvent for the vat color.

2. Method of discharge printing fabric which comprises treating a dyed fabric containing organic derivatives of cellulose with a printing paste containing a reduced vat color, zinc formaldehyde sulfo-xylate, a swelling agent for the fabric under treatment, a glycol derivative,

sodium oxalate, caustic soda, and a thickening agent, said paste having been prepared at least twenty four hours before use, and then passing the fabric through a Mather Platt for 10 minutes under moist conditions.

3. Method of discharge printing fabric which comprises treating a dyed fabric containing organic derivatives of cellulose with a printing paste containing a reduced vat color, zinc formaldehyde sulfoxylate, phenol, dithio glycol, sodium oxalate, caustic-soda and a thickening agent, and then passing the same through a Mather Platt for 10 minutes under moist .conditions.

4. Method of discharge printing fabric which comprises treating a dyed fabric containing cellulose acetate with a printing paste containing a reduced vat color, zinc formaldehyde sulfoxylate, a swelling agent for the fabric under treatment, a glycol derivative, sodium oxalate,

caustic soda and a thickening agent, and then passing the same through a Mather Platt for 10 minutes under moist conditions.

5. Method of discharge printing fabric which comprises treating a dyed fabric containing cellulose acetate with a printing paste containing a reduced anthraquinone vat dye, zinc formaldehyde sulfoxylate, a swelling agent for the fabric under treatment, a glycol derivative, sodium oxalate, caustic soda and a thickening agent, and then passing the same through a Mather Platt for 10 minutes under moist conditions.

6. Method of discharge printing fabric which comprises treating a dyed fabric containing cellulose acetate with a printing paste containing a reduced anthraquinone vat dye, zinc formaldehyde sulfoxylate, phenol, dithio glycol, sodium oxalate, caustic soda and a thickening agent, and then passing the same through a. Mather Platt for 10 minutes under moist conditions.

7. Method of discharge printing fabric containing an organic derivative of cellulose which comprises treatinga dyed fabric with a printing paste containing phenol, a vat color, a penetrating agent which is also a solvent for the vat color and a. reducing agent.

8. Method of discharge printing fabric containing an organic derivative of cellulose which comprises treating a dyed fabric with a printing paste containing alcohol, a vat color, a penetrating agent which is also a solvent for the vat color and a reducing agent.

GEORGE BIVAT. 

